Grab a stick from outside, and then just start gluing colorful pom poms onto a Styrofoam ball. I dare you to find an easier kid-friendly craft. With a large enough family (or by letting kids make two or three trees each), you can quickly have your own miniature forest in your living room. (Original source: http://www.oneartsymama.com/2011/09/trees-pom-poms-and-playdohoh-my.html)